Morpholine azo dyestuffs



Patented Sept. 22, 1953 UNITED STATES.v PATENT OFFICE Mordecai Mendoza, Blackley, Manchester, Eng- 7 land, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain No Drawing. Application July 16, 1951, Serial No. 237,073. In Great Britain August 3, 1950 1 This invention relates to new azo dyestuffs and more particularly it relates tonew disazo dyestuffs useful in dyeing leather-in brown-shades.

According to the invention I provide new disazo dyestuffs of the formula:

wherein Ar stands for an aromatic residue of the benzene or naphthalene series which optionally may bear substituents.

According to a further feature of the invention I provide a process forv the manufactureof the said new disazo dyestuffs which comprises coupling one molecular proportion of a diazotised arylamine monosulphonic acid with one molecular proportion of resorcinol in a medium which is acid to litmus and coupling with the so-produced monoazo compound in alkaline medium one molecular proportion of adiazotised orthoor para-aminophenyl-morpholirie'.

The said new dyestuffs dye vegetable-, mordantor semichrome-tanned leather in brown shades of good strength and of excellent stability towards acids and alkalis.

The invention is illustrated but not limited by. the following examples in which the parts are;

by weight.

Example 1 4 Claims. (Cl. 260152) is continued for 4 hours in litmus acid medium. The mixture is cooled to below 5 C. and an aqueous solution of the diazonium chloride obtained from 17.8'parts of o-aminophenylmorpholine is added to it. Caustic soda solution is added .in amount suflicient to make the mixture alkaline to glazed red litmus paper and the mixture is stirred for 12 hours. 1 Sufficient common salt to makea 20% brine is then added followed by hydrochloric acid to make the reaction neutral. The precipitated disazo dyestuff is filtered ofi, dried and ground. The dark brown powder so obtained is soluble in water and the solution dyes leather in reddish tan brown shades of good all round properties of fastness. If in place of the o-aminophenyl morpholine used in the process of the above example there is used-p-aminophenylmorpholine the resulting disazo dyestuff yields greener shades on leather of similar good properties.

structurally, the dyestuffs prepared according to the foregoing may be shown by the following formula:

sion is addeda solution of 11 parts of resorcinol in 100=parts of water. Sodium acetate is added to the mixture until the mineral acid reaction no longer persists and stirring is continued for about 6 hours. The suspension so obtained is cooled to 5 C. and the aqueous solution of the diazonium chloride obtained from 17.8 parts of p-aminophenylmorpholine is added. Caustic soda solution is added in amount suflicient to make the reaction of the mixture alkaline and stirring is continued for about 12 hours. The disazo dyestufi formed is isolated in manner similar to that described in Example 1 and it dyes leather in redbrown shades of good fastness properties. It may 3 d be structurally represented by the following for- What I claim is: mula; 1. Disazo dyestufis of the formula:

SOaH OH HOaSAr-N=N H N=N UHF-CH1 N=N GHFCEZ H a H H NN E wherein Ar stands for a radical selected from the 011 N group consisting of monoand dicyclic aryl CHPO'HZ radicals of the benzene and naphthalene series. H 2. @Disazo dyestuffs of the formula:

CHz-CH CHPCHI Example 3 3. Disazo dyestuffs of the formula:

A solution of '7 parts of sodium nitrite in 50 S0311 parts of water is added at "room "temperature to a stir-red suspension of 2-323 parts of 3-amino- 6- hydroxy-S-sdlphobenzoic'aeid in -a mixture of 360 parts of water an'd'25 parts of 2,36 :aqueous solution of hydrochloric acid and to the mixture 7. there is added *a so'lut'ionof -11 parts of resorci-nol I]\I:N in 100 parts of "Water. Sodium acetate "is :added to the mixture until the mineral acid reaction :no longer persists and stirring is continued for CHPGEH about :12 'hours. The suspension so obtained is cooled to 5 C. and the aqueous solution of the diazon'ium chloride obtained from 17.8 parts of 40 o-amin'ophenylmorpholine is added. Caustic soda solution is added ina mount sufiicientto make the 4. Disazo dyestuffs of the formula:

I .N=l ouwom OH N/ 0 \CH2C2 H reaction of the mixture alkaline and stirring is MORDECAI MENDOZA. continued for a further '12 hours. The disazo dyestufi formed 1s isolated as described 1n Ex- References Cited in the file of this patent ample 1. It glves yellowish tan brown shades on leather of good f-as'tness properties and may UNITED STATES PATENTS be represented by the following structural for- Number Name Date 2,269,218 McNally et 2.1. t Jan. 6, 1942 v 03H H om-0H,

en-P011, 

2. DISAZO DYESTUFFS OF THE FORMULA: 